Apparatus for casting high-fusing metals



C. LAING.

APPARATUS FOR CASTING HIGH FUSING METALS. APPLICATION FILED MAYSI, 1917. RENEWED OCT. 28. 19-18.

1,307,Q99. Patente d June 17, 1919.

tlrtoz mango CLAYTONTL AING, OF CHICAGO, ILLINOIS.

APPABATUsro CASTING HIGH-FUSING METALS.

Specification of Letters Patent.

int-tented June 17, ion).

Applicationfiled May 31, 1917, Serial No. 171,852. Renewed October 28, 1918. Serial No. 260,064.

To all whom it may concern:

- Be it known that I, CLAYTON LAING, a

subject of the King of Great Britain, re-

siding at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Apparatus for Casting High-Fusing Metals, of which the following is a specification, reference-being had therein to the accompanying drawings. ThlS inventlon relates to the casting of high' fuslng metals and 1n casting by gas pressure methods, the investing material being of necessity porous, it is necessary to hermetically seal the crucible end of the mold, from the edge of the ring or flask to the sprue' hole, inorder to concentrate the pressure on the molten metal Within the mold. Any previous attempt at sealing the mold end was iinqoracticalfor the following reasons :On casting, the sprue hole in the crucible was cast full of metal, which necessitates either destroying the crucible or reheating the metal to a molten state to remove the remaining button and sprue, thus cast into the crucible. Also, it is often desirable to attach two or more sprues to a large casting or to'invest two or more small castings in one mold, which was impossible. Again, in heating up the moldto dry out the investment and dissipate the wax pattern, the steam genera-ted had no outlet except from a minute sprue hole in the crucible and tend ed to blow out the crucible or the invest ment.

These difficulties applicant has overcome by a crucible of such design as to permit of the use of any desired number of sprues at an angle, the easy removal of residue gold, as well as furnishing an adequate vent for the escape of steam in the heating up process.

From a structural standpoint, my invention also includes a novel positioning ring and crucible, both of which are indispensible for accurate investment and casting in connection with high fusing metals. The article and the method involved in connection therewith will be hereinafter specifically described and then claimed, and reference will now be had to the drawing, wherein Figure 1 is a vertical view of an inverted investment ring relative t? a positioning ring, showing these parts 'ln position preparaitory to casting;

i Fig. 2 is a vertical sectional view of the investment ring in upright position showing the positioning ring and sprue formers removed and a globule or button of metal in position ready to be subjected to heat;

Fig. 3 is a similar view showing a metal cast; V i

Fig. 4 shows views of the positioning ring;

Fig. 5 shows views of the crucible, and

Fig. 6 is a vertical sectional view of an investment having a plurality of sprue openings which have permitted of metal being cast in connection with large piece of work.

Considering the structural elements of my invention, 1 denotes a metallic investment ring, having a bore 2 with one end thereof enlarged to provide-an annular seat 3. This investment ring is adapted to contain an investment 4 of the usual porous material.

5 denotes a positioning ring having the peripheral edges thereof provided with opposed upstanding lugs 6. Centrally of the investment ring is a cup 7 and surrounding the cup 7 is an annular upstanding flange 8. The cup 7 is adapted to contain wax or other plastic material 9 for holding sprue rods or wires 10 on the ends of which areiiashioned or placed wax patterns 11 corresponding in shape and contour to the objects to be cast within the investment 4.

12 denotes a conveXo-concave crucible having a central large opening 13, and a pcripheral lateral flange 14 adapted to engage the seat 3 of the investment ring. Prior to placing the investment 4 within the ring 1, the crucible is placed on the positioning ring, the peripheral flange 14 resting on the outstanding flange 8 of the ring 5, which allows the central portion of the concave surface of the crucible to engage the soft wax 9 in the cup 7, forming a seal of the central opening 13 of the crucible.

Sprue wires 10, at one end of which are attached the wax patterns 11 are now thrust into the wax 9 through the opening 13 of the crucible to their desired position relative to the mold, the soft wax supporting them and acting as a seal of the central opening 13 of the crucible. The ring is then placed on the crucible, the flange 14 of the crucible supporting it at the annular seat 8. The investment material is then poured. It will be noted that the central portion of the crucible end of the mold and the sprue openings are thus formed by the investment material.

The outstanding lugs 6 on the ring 5 permit of the whole being easily picked up or handled before the investment is set. When the investment has set, 'the ring 5 is removed, the exposed ends of the sprue wires heated and pulled out and the mold heated to dry out the investment and dissipate the wax patterns.

Fig. 2 shows the deviceat this stage with the metal 15 in position to be fused and injected into the mold. lVhen the metal is brought to a molten state and the gas pressure applied, the sealof the end wall of the mold is accomplished by the impervious crucible and the molten metal, which seals the otherwise exposed investment material at the bottom and center of the crucible.

By virtue of the excess of metal used in casting a mold there is always a globule or button 16 remaining in the crucible as shown in Fig. 3. Thus the gas pressure is concentrated on the metal within the mold and maintained while it is congealing.

As further illustrating the advantages of the large central opening in connection with the impervious crucible, there is shown in Fig. 6 an investment in which a large piece of work 17 has been east through the medium of a plurality of sprue openings 18. Since the base of the crucible and openings to the sprue channels are formed by the in vestment material, the number of sprues and the angles at which they are placed may be determined wholly from the requirements of the individual piece of work to be cast.

On removal of the finished casting, the sprues being surrounded by the .loose investment material, the residue metal is easily req i of is p te -m y h b in d e moved from the crucible by severing the sprues.

What I claim is 1. Amold having sprues, and a crucible on said mold having an opening of larger diameter than the diameter of the sprues used in the mold.

2. As a new article for the manufacture of castings in an investment material, a mold formed of investment material and having sprue channels, and a crucible of impervious material on the mold having an entrance to said sprue channels inthe investment material and adapted to ha e h trance lined by the investment material of the mold.

3. A crucible for a mold containing porous material and having a gate with the porous material of said mold forming alining for the gate.

l. A device for casting high fusing metals consisting of an investment ring, an invest ment therein, and a crucible on said ring engaging said investment and providing a gate formed by the investment extending into saidcrucible.

5. A device of the type described comprising an investment ring adapted to contain an investment, a crucible for said ring having a large sprue opening, a positioning ring for said crucible and said investment ring, and means carried by said positioning .rinw ada ted for ositionim srue formers in the sprue openingof said crucible and furnishing a seal for said opening.

In testimony whereof lafifix my signature in the presence of two witnesses.

CLAYTON 'LAING. Witnesses;

J. E. WHmMaN, KARL H. BUTLER.

five centseach, py addressing the {Commissioner 0,1? lw tents, Washington, 1). C. 

